This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Pediatric infection with Neisseria meningititidis remains an important cause of serious illness with neurologic sequellae for which conventional vaccination has been ineffective. Both neutralizing and bactericidal antibodies are protective but the infant immune system does not respond adequately to capsular polysaccharide immunogens. This project tests several meningococcal immunogens formulated with different adjuvants designed to improve the bactericidal antibody response in the infant host. Infant rhesus monkeys, screened for absence of meningoccal antibody and housed in a natural environment, the outdoor field cage, will be immunized with meningococcal vaccines at 3 months of age, followed by a booster injection at 4 months. The titers of bactericidal antibody will be measured in this immunogenicity study.